Boxing is a money making industry whose best days may be arguably behind it. However, some of the discipline’s best have given MMA a try with somewhat mixed results. This list gives some of the best who have given MMA a try. Just to list the criteria, these fighters are ranked on their accomplishments in boxing and not their accomplishments in MMA. So with that, here we go:

10. Erin Toughill

Erin Toughill has two unique distinctions on this list. First of all she’s only one of two woman on this list. Second, she has the only distinction of starting out in MMA and crossing over into boxing to have a successful career. Toughill actually went undefeated in boxing until her 2005 bout with boxing legend Laila Ali, the daughter of a legend in his own right, Muhammad Ali.

It was actually a defining match in both fighters’ careers as both women would retire from boxing within the next two years and Toughill would move onto MMA full time, having split her time between the two sports until that point.

9. Jan “The Giant” Nortje

Jan “The Giant” as he is known, originally split his time between boxing and kickboxing, namely for the K-1 promotion during its’ heyday. The South African Nortje makes it on this list specifically because he has the distinction of being the boxing All-African Heavyweight Champion.

His boxing career was also successful in that he went undefeated at a perfect 11-0. He had nowhere near that success in MMA where he went 2-4, mostly in Japan, but once in America under the Strikeforce banner with a win against Bob Sapp. He recently returned from a five year K-1 layoff.

8. Mike Bernardo

Another boxer to crossover into kickboxing, Mike Bernardo is unique on this list since he’s the only deceased member. However, that in no way takes away from his legacy in the two sports in which he excelled.

In boxing he compiled a record of 11-1-1 and in the last match of his boxing career won the World Boxing Foundation World Heavyweight Title. It was during the heyday of his kickboxing career and six months after his last boxing match that he participated in his only MMA match at Inoki Bom-Ba-Ye 2001. The match ended in a draw against Nobuhiko Takada.

7. Eric “Butterbean” Esch

Despite his rotund figure, Butterbean holds a few distinctions on this list. The first is that he’s the only member of this list to crossover from boxing into MMA and earn a title, winning the Elite-1 MMA Super Heavyweight Championship on May 7, 2011 and having gone 17-10-1.

The second is that he’s one of only two active boxers on this list, having fought an average of one boxing match a year between 2006 and now. He also had a brief foray into kickboxing between 2003 and 2009 going a total of 3-4. In the sport of boxing with his figure, one could consider him the sport’s equivalent of Roy Nelson having a record of 77-10-4 and having captured the IBA World Super Heavyweight Championship and the WAA World Heavyweight Championship.

6. Ricardo Mayorga

Ricardo Mayorga is a recent example of boxers making a move into MMA after their boxing careers are finished. Mayorga’s accomplishments include a boxing record of 29-8-1 1NC and having held four different welterweight championships with The Ring, WBA, and WBC organizations as well as the WBC Junior Welterweight Championship.

His MMA career though has been the subject of much controversy. He was supposed to make his MMA debut in 2010 against Din Thomas for Shine Fights but was blocked by boxing promoter Don King. When he finally did make his debut on May 3 of this year, it was ruled a no contest when Mayorga made an illegal kick to the spine and at World Series of Fighting: South America, was choked out by opponent Rene Martinez.

5. Holly Holm

Without a doubt, Holly Holm is probably one of the more decorated boxers to make her way into MMA. Over her eleven year boxing career, she’s gone 33-2-3 with a total of 18 championships over three weight classes to her name. In addition she has a kickboxing background, which has only made her a force to be reckoned with in MMA.

All four of her fights have been wins and all four have been finishes, namely one under Bellator and one under Legacy FC. The only reason why Holm isn’t higher on this list is that at 31 years of age she still has time to develop her career in MMA.

4. Art Jimmenson

Art Jimmenson is a part of MMA history despite only fighting once at UFC 1 on November 12, 1993 as the first round match against Royce Gracie. Jimmenson was the only boxer on the fight card and was offered the largest show check at around $2000 US. He is most known for having only one glove on his jab hand and for taping out when Royce simply took him down and mounted him.

Jimmenson returned to boxing immediately thereafter, retiring from boxing in 2002 after going 33-18, and having won the IBC Americas Light Heavyweight title once. He’s now the head boxing instructor at the UFC Gym in Torrance, California.

3. Ray Mercer

Ray Mercer is one of two Olympic Gold Medalists on this list, having won it in the 1988 Seoul Games. He went on to have a successful career in professional boxing, going 36-7-1 and having won the IBF Inter-Continental, NABF, and WBO heavyweight championships. However, he initially tried his luck at kickboxing in K-1 and received losses from Musashi and Remy Bonjasky before realizing it wasn’t for him.

He then went onto fight in an exhibition match under the Cage Fury FC banner against brawler Kimbo Slice, losing a surprising guillotine choke, then knocking out Tim Sylvia in nine seconds. The last that was heard of his MMA endeavors, Mercer was signed by King of the Cage in 2010.

2. James Toney

Probably the most distinguished active boxer on this list, James Toney has held a boxing title as recently as 2009. In total, Toney has held 13 different titles over five weight classes. His only MMA appearance was at UFC 118 in probably the most recent example of the UFC engaging in a freak show, matching him up against legend Randy Couture.

Though billed as a Boxing vs. MMA fight, it was really more Boxing vs. Wrestling as Couture pulled a low single (not commonly used in MMA) and proceeded to ground and pound Toney before submitting him in an arm triangle. There was later an attempt to book a fight between Toney and legend Ken Shamrock but the bout never materialized.

1. Muhammad Ali

“Wait a minute, what?” You’re probably asking. Yes, Muhammad Ali competed decades before the UFC was created. However, on June 26, 1976 he competed in a match that in Japan is legendary and would forever have an impact on Japanese Mixed Martial Arts; a match against pro-wrestler Antonio Inoki.

The fight itself was uneventful as Ali’s camp had special rules put in place that Inoki couldn’t grapple or throw high kicks anywhere but with one knee on the ground. The match was eventually called a draw, with Inoki’s right foot broken from all the kicks he was throwing and Ali’s left leg swollen with an infection and two blood clots. However, the two fighters became friends and legends afterwards.